Means for charging accumulators.



Y No., 697,193. Patented Apr. 8, I902. R. E. BALL.

MEANS FOR CHARGING ACCUMULATORS.

(Applicution filed July 1, 1901.) (No Model.)

2 Sheets-Sheet I.

/1 $111 R LEG l9.

10013 A BOD IF Royall E. Ball i W v wonmrmo" WASHINGTON u c N0. 697,!93.Patented Apr. 8, I902. R. E. BALL. MEANS FOR CHARGING ACCUMULATURS.

(Application filed July 1, 1901.)

2 Sheets-Sheet g.

(No Model.)

Royal E. Ball UNITED STATES PATENT OFFICE.

ROYAL EDWARD BALL, on NEW YORK, N. Y.

MEANS FOR CHARGING ACCUMULATORS.

SPEGIFICATION part of Letters Patent No. 697,193, dated April 8, 1902.

Application filed July 1, 1901, Serial No. 66,6411. (No model.)

To aZZ whom it may concern.-

Be it known that I, ROYAL EDWARD BALL, a citizen of the United States,residing at the city of New York, in the county and State of New York,have invented a certain new and useful Means for Charging Accumulators,of which the following is such a full, clear, and exact description aswill enable any one skilled in the art to which it appertains to makeand use the same, reference being had to the ac companyiug drawings,forming part of this specification.

My invention relates more particularly to apparatus for chargingaccumulators by means of alternating current; and it consists, in part,in varying the resistance or counterelectromotive force of theaccumulalor to be charged with the variations in electromotive force ofthe charging-current. This I may accomplish by suitably varying thenumber of cells in circuit with the variations in tension of thecharging-current. For the purpose of so varying the number of cells incircuit automatically and in a suitable degree I have invented theapparatus described below. The method of charging accumulators heredescribed forms the subject of another application for patent filed byme of even date with this one.

The object of my invention is to provide a means for imparting to theunits or cells composing an accumulator or storage battery asubstantially uniform charge by the use of alternating orregularly-pulsatin g currents of variable electromotive force.

In the drawings, in which like characters of reference refer to similarparts in the different views, Figure l is a side view of an apparatusembodying my invention. Fig. 2 is a diagram which will be found usefulin explaining the operation of my apparatus. Fig. 3 is a diagram of acommutator forming part of the apparatus shown in Fig. 1, and Fig. 4 isa diagram of a modification of the commutator shown in diagram in Fig.3.

In my invention I commutate the cells of the storage battery by apeculiar commutator, so that the number of cells in circuit is at anyperiod in direct proportion to the electromotive force of the wave ofalternating-current supply. Thus, for example, while the clcctromotiveforce of the altemating-current wave is less than two volts and if anyof the battery units were in circuit they would tend to dischargethemselves through the circuit instead of being charged by the currentflowing therein no cells are in circuit. WVhen the current attainsbetween two and five volts, one cell is in circuit, when between fiveand eight volts are attained two cells are in circuit, when betweeneight and eleven volts are attained three cells are in circuit, and soon progressively upward to the crest of the alternating wave, whence thenumber of cells in circuit is progressively reduced in proportion to thenow-falling electromotive force until the point of no electromotiveforce is reached, when by a reversal of connections the progressivecutting in and out of cells is repeated on the negative wave of current.

It will be noticed from the above thatl recommend a chargingelectromotive force per cell somewhat higher than it is customary to usein constant-electromotive-force practice. The reason for this is, aswill be understood later, that by my method each of the cells thatconstitute the battery is in circuit but one-half the time, andtherefore can receive during such period a rate of charge higher than iscustomarily employed.

Referring first to Fig. l of the drawings, 10 is the base, at one end ofwhich is situated the standard 11, throughwhich projects horizontallythe stud 12, having upon it the sleeve 13, preferably composed ofinsulating material and carrying a handle 14 for purposes of adjustment.This sleeve 13 carries an ordinary reversing-commutator, composed of theconducting-segments 15 and 16, separated electrically from each other bydiametrically opposite insulating-segments 17. Upon thisinsulating-sleeve 13 is also carried a second commutator 18, of peculiarconstruction, to be hereinafter described. This commutator 18 is dividedinto two main portions by the insulating-segments 19, placed atdiametrically opposite points thereof. The opposite end of the base 10carries upon a standard 20 a synchronous motor 21 of anyordinaryconstruction. Uponthecollecting-rings 22, situated upon theshaft of this motor, bear brushes 23, to which are attached thesecondary mains 2i of an alternating-current circuit, which includes atransformer 25, the

.primary mains of which are shown at 26.

From the collecting-rings 22 lead the conductors 28, which pass throughthe horizontal arms 31 and 32, carried at opposite extremities of avertical arm 30, keyed upon theopposite ends of the motor-shaft fromthat upon which the contact-rings 22 are situated. The arms 32 and 31carry, respectively, brushes 33 and 34, which bear, respectively, uponthe segments 15 and 16 of the reversing-commutator 18. The conductors 28are attached to these brushes 33 and 34, which are adapted to be rotatedby the motor 21 over the commutators above described.

Fig. 3 representsin diagram these two commutators and their connections.It will be seen that the commutator 18 is composed of two sets ofchordal barsA B O D and G H L R. These bars'are insulated from thoseadjacent to them, and. between the two central bars D and G is situatedthe broad insulating-strip 19, above described, which divides thecommutator intotwo parts, each of which composes approximately one-halfof said commutator. The brush 33 is adapted to bear upon the segmentalends of these bars, and the brush 34 is adapted to bear upon thesegments 15 and 16 ofthe reversing-commutator. Each one of the sets ofbars composing onehalf of the commutator 18 is cross-connected to one ofthe bars in the other set. Thus A is connected with G by means of theconductor 45, B with H by the conductor 46, C with L by the conductor47, and D withR by the conductor 48. These cross connections are for thepurpose'of simplifying the apparatus and obviating the necessity ofconnecting each half of the commutator by separate conductors with theaccumulator, as will be understood from the following description:

M N O P Q are cells or units composing a storage battery or accumulator.The cell M has one of its elements connected by means of a conductor 36to the segment 16 of the reversing-commntator, and the cell Q has oneof. its elements connected by means of a conductor 37 with the segment15 of the reversing-commutator. The remaining elements of the cells Mand Q and the elements of the cells N, O, and Pare connected in seriesin the usual manner, and each couple so electrically connected in seriesis electrically connected by means of the wires 38, 39, 40, and'41 withone of the bars A B C D, composing a part of the commutator 18. Theseconnections furnish the means for passing a current through theaccumulator.

The operation of this apparatus is as follows: Referring to Fig. 2,which shows a diagram of the electromotive force of analternating-current wave and indicates the position of the brush 33 uponthe segmentsot' the commutator 18 at any moment during the rise and fallof such electromotive force, and keeping in mind the diagram of Fig. 3,we will suppose that the brushes start in the position as shown in Fig.3that is, the brush current will flow from thebrush 33 through theconductor 41 to the cell M and after passing through said cell throughthe conductor 36 to the brush 34 by means of the reversingcommutatorsegment 16, as the brushes advance in synchronism with the rise of theelectromotive force of the current, so as to bring the brush 33 intocontact with bar 0. It will be seen that we now have two cells M and Nin circuit, and at the sametime by referring again to Fig. 2 it will benoticed that in position 0 the electromotive force of the current isapproximately twice as great as in position D. Similarly by continuingto revolve the brushes in sychronism'with the wave of alternatingcurrent the successive cells are cut into circuit as electromotive forceincreases until we reach the apex of the electromotive forcecorresponding to the.

position A in Fig. 2 and the bar A in Fig. 3.

From this point on for a quarter-cycle the electromotive force of thepositive wave is decreasing, and at the same time the cells areprogressively cut out of circuit in an order reverse to that in whichthey were cut in in proportion to the diminishing electromotive force bythe passing of the brush 33 successively over the opposite ends of thebars B, C, and D until it reaches the end of the bar D. Here it may besupposed that the electromotive force has dropped to two volts and thatif the last cell were left in circuit it would begin to dischargeitself. This is prevented, however, by the brush 33 coming in contactwith the insulating-bar 19, which breaks the circuit during the time theelectromotive force of the current is below the given limit. Thus allthe cells are out of circuit until the electromotive force has fallen totwo volts on the negative curve. At this point a change takes plaoe, andthe brush 34 now rests upon the segment 15 of the reversing-commutator,while the brush 33 passes to the bar G on the commutator 18. Thisreverses the battery connections, so that the negative wave passesthrough the cells in the same direction as did the positive wave. Thecells are now, however, switched into and out of circuit progressivelyin the reverse order to that above described-that is, the cell Q, whichwas not before in circuit, is the first to be cut in, and by theprogressive movement of the brush 33 over the bars G, H, L, and R thecells P, O, and N are successively cut into circuit in the order nameduntil the apex of the negative Wave is reached, whence onward theyaresuccessively cut out-of circuit in a manner similar to that abovedescribed in connection with the cutting inand out of the cells on thediminishing positive wave. It will thus be seen that the cell-M wasfirst on circuit constantly during onehalf of a cycle and that it wasthen cut out of circuit and the cell Q cut into circuit duringapproximately the remaining half of the cycle. Thus the cells M and Q,have been in circuit approximately for equal lengths of time and havereceived approximately equal charges. The same may also be said of thecells N, O, and P, which have been cut into and out of circuitprogressively, as above described. This may be demonstrated by thefollowing calculation: Disregarding the length of time required for thebrush 33 to pass over the insulating-bar 10 and calling the times inwhich the brush is passing over the bars D, C, B, and A equal, we havethe following, in which the first column represents the block the brushis upon, and the second column rep resents the cells in circuit:

o..... M N

M N o M N o P 4A.. M N o P M N o n..... P e

o P e an N o P (.3

ea. N o P o O P Q n..... P o

s s s s s It will thus be seen that during a complete cycle each cell isin circuit for the same aggregate length of time, and as the current isalways in the same direction it follows that the cells must be uniformlycharged.

Fig. 4: shows a modification of the commutator shown and described inconnection with Fig. 3. It is necessary that the commutator shown anddescribed in Fig. 3 should rotate completely once for every cycle ofalternating current passed through the battery. In the majority of casesin practice this would be too high a speed, and therefore in Fig. tisshown a commutator by which the same results will be produced when thecommutator rotates once for every two cycles of alternating current.This commutator, instead of having but a single set of bars A B O D andG H L R, has two sets of bars A B O D and G H L R and A B C D and G H LR crossconnected with each other in substantially the same manner asshown in Fig. 3, and in correspondence with this duplication of parts ofthe commutator 18 the reversing-commutator segments 15 and 16 are alsoduplicated, as shown at 15 and 16, the segments 15 and 15 and 16 and 16being connected with each other by means of the conductors 44: and a3,respectively. The position of the brushes 33 and 3t and the operation ofthis commutator is similar to the operation of the commutator shown inFig. 3, with the exception that the brushes rotate but once around thecommutator for each two cycles of the alternating current supplied.

For the purpose of simplicity I have here shown the commutator 18constructed of a number of chordal bars; but it will be understoodthatin practice it will be constructed in the ordinary manner of anumber of segments properly connected by wires.

It is evident that by reversing the operation described and using thestorage battery as a source of supply a sinuous alternating current canbe derived from the direct current from the storage battery. It willalso be noticed that the apparatus can be used for sup plying continuouscurrent for lighting and power, the storage battery in this caseintegrating and averaging the alternating current to a uniformelectromotive force.

Having fully described my invention, what I claim as new, and desire tosecure by Letters Patent of the United States, is

1. An accumulator composed of a plurality of units, an electric circuitconnected therewith, means for varying the number of said units incircuit by cutting said units into and out of circuit in a predeterminedorder, and means for varying the number of said units in circuit bycutting said units into and out of circuit in an order reverse to saidfirstnamed order.

2. An accumulator composed of a plurality of units connected in series,an electric circuit connected therewith, means for varying the number ofunits in said series connection in circuit by cutting said units intoand out of circuit in a predetermined order, and means for varying thenumber of said units in said series connection in circuit by cuttingsaid units into and out of circuit in an order reverse to saidfirst-named order.

3. An accumulator composed of a plurality of units connected in series,an electric circuit connected therewith, means for varying the number ofsaid units in circuit by cutting said units into and out of circuit in apredetermined order, means for automatically breaking said circuit, andmeans for varying the number of said units in circuit by cutting saidunits into and out of circuit in an order reverse to said first-namedorder.

4:. An accumulator composed of a plurality of units, a circuit forpassing through said accumulator a current of fluctuating electrometiveforce, automatic means for increasing the number of said units incircuit during the rise in electromotive force of said current anddecreasing the number of said units in circuit during the fall inelectromotive force in said current, and automatic means forinterrupting said current in said circuit when its electromotive forcefalls below the electromotivc force of one of said units.

5. An accumulator composed of a plurality of units, a circuit forpassing through said accumulator a current the electromotive force ofwhich rises and falls in a series of waves,

means for progressively increasing and de-' creasing the number of unitsin circuit in a predetermined order during the rise and fall of one ofsaid waves, and means for progressively increasing and decreasing thenumber of units in circuit in an order reverse to said first-named orderduring the rise and fall of the succeeding wave.

6. An accumulator composed of a plurality of units, an electric circuitconnected therewith, a reversing-commutator in said circuit, acommutator for increasing and decreasing the numberof units in saidcircuit, brushes bearing upon said commutators and connected with saidcircuit, and means for producing rotation between said brushes andcommutators in synchronism with the fluctuations in electromotive forceof-the current flowing in said circuit.

7. An accumulator composed ofa plurality of units, an electric circuitconnected therewith, a reversing-commutator in said circuit, acommutator for varying the number of units in said circuit, a brushconnected to one side of said circuit and adapted to bear upon saidfirst-named commutator, a brush connectedto the other side of saidcircuit and adapted to bear on said last-named commutator, and means forproducing rotation between said commutators and brushes in synchronismwith the fluctuations in electromotive force of the current flowing insaid circuit.

8. An accumulator composed of a plurality of units connected in series,a reversing-commutator, connections leading from the segments of saidreversing-commutator to the end elements of said series-connected units,a second commutator, connections leading from the segments of saidsecond commutator to the intermediate points in said series connection,brushes bearing on said commutators, and means for producing rotationbetween said commutators and brushes.

In testimony whereof I have'hereunto set my hand and affixed my seal inthe presence of the two subscribing witnesses.

ROYAL EDWARD BALL. [n s.]

WVitnesses:

J. S. BELL, W. H. TAYLOR.

